Enhanced mechanical load limit of CORC cable under transverse compression and axial tensile loads

Abstract

The winding core of CORC (conductor on round core) cables is crucial for resisting mechanical deformations. While different winding core structures can influence the maximum load capacity of these cables, the specific impact of changes in the winding core structure on the mechanical properties of superconducting cables remains unclear. This paper establishes 3D mechanical models of CORC type cables, especially realizes the modeling of the interlocking core structure for the first time and analyzes the mechanical behaviors of these cables under transverse compression and axial tensile loads. It discusses the effects of the winding core structure and the number of inner copper tapes between the winding core and the high-temperature superconducting tape on the mechanical load limits of CORC cables. The results show that CORC cables exhibit enhanced performance in transverse compression and axial tension when a tube core is used for transverse loads and a spiral core for axial loads. The axial strain of the superconducting layer increases as the number of inner copper tapes increases in the transverse compression case, and it decreases as the number of inner copper tapes increases under axial tensile loading. Furthermore, the effect of an arc load block structure on the transverse compression performance of CORC cables is also investigated. The results reveal that the optimal contact angle for achieving optimal transverse compression performance in CORC cables with an arc block structure is approximately 5°. The decrease in the current-carrying capacity of cables in the arc block structure is mainly caused by the combination of compressive strain at the contact area and tensile strain at the contact edges. The numerical results can provide a basis for the reasonable selection of the structure of coil former when the winding CORC coil magnet.